front brake problem

[mark]

a few days ago a slight rubbing noise appeared from the front passenger brakes , jacked it up turned the wheel and it felt a little stiff , so off with the wheel , off with the caliper and checked the pads , pads seem fine ( lots of pad left ) disc seemed fine , cleaned the caliper and surrouding parts and reassembled ....
hub spins fine until we press the brake and then the problem returns

For some reason the piston within the caliper is not retracting after pressing the brake i.e. the hub is very hard to turn as is pressure is still being applied to it even when the brake pedel is released

is there some sort of pressure releif valve or how do the pistons retract under normal operation ??

any help gladly recieved

mark

[charged_rs]

a few days ago a slight rubbing noise appeared from the front passenger brakes , jacked it up turned the wheel and it felt a little stiff , so off with the wheel , off with the caliper and checked the pads , pads seem fine ( lots of pad left ) disc seemed fine , cleaned the caliper and surrouding parts and reassembled ....
hub spins fine until we press the brake and then the problem returns

For some reason the piston within the caliper is not retracting after pressing the brake i.e. the hub is very hard to turn as is pressure is still being applied to it even when the brake pedel is released

is there some sort of pressure releif valve or how do the pistons retract under normal operation ??

any help gladly recieved

mark

mark , sometimes the pistons do sieze but thats down toage and wear really.

usually the discs look fine from first glance but the only real way to check is to feel round the back of the disc and if there is a lip / ridge on the very edge of the brake disc, then its new discs time.


are your sliders in good order and properly greased up ? nice and shiney ?

[mark]

are your sliders in good order and properly greased up ? nice and shiney ?

hi , do you mean the piston ??

we rubbed the piston down a little but we didn't grease them

thanks

mark

[sabik]

Having the same problem myself..... was just working at it this evening... got a set of calipers but there for a mk1 and I'm driving a mk2 and i discovered there a little small, but did try bleed out the system to see if it could help, don't think it helped but haven't taken it for a good spin.

Not sure what way to go at it now... but still think it the calipers...

Grrrr.... (but at least there's someone else feeling my pain and the weather ain't great!)

if there's anyone in the south east might want to pop in I'll make tea and coffee...

[charged_rs]

are your sliders in good order and properly greased up ? nice and shiney ?

hi , do you mean the piston ??

we rubbed the piston down a little but we didn't grease them

thanks

mark

on the front calipers , yes , you have a piston but...
the shiney silder at the top and the 10mm slider you undo to be able to swivel the caliper up - those are your sliders , and usually the bottom one corrodes and gets lumpy and cruddy.

if they are anything other than shiney and smooth and well lubed with red rubber grease then you have probs. - its an easy fix , but check your sliders. Rubbing your piston at this stage is pretty pointless , as the bits that seize the piston are behind the rubber

there are alot of mechanics that use copper grease on the slider but this in itself causes issues as copper grease tends to cake up with time.
Dont ever use coppergrease on your caliper sliders.
Red rubber grease is the shit when it comes to lubing the sliders , ive used it for years and never had issues

[Steve]

Having the same problem myself..... was just working at it this evening... got a set of calipers but there for a mk1 and I'm driving a mk2 and i discovered there a little small, but did try bleed out the system to see if it could help, don't think it helped but haven't taken it for a good spin.

Hi Glen,
Try swopping the calipers over, left to right, then should then be the right way up.
You have a PM.
Steve

[sidewaysreilly]

there are alot of mechanics that use copper grease on the slider but this in itself causes issues as copper grease tends to cake up with time.
Dont ever use coppergrease on your caliper sliders.
Red rubber grease is the shit when it comes to lubing the sliders , ive used it for years and never had issues


use neverseize by bostic..................full of copper, zinc and graphite. Its the bizzzzzzzzzzz

[sabik]

Hi Mark, well after last nights bleeding I got the car out for a few local spins this evening and all seem to be going ok.. Just did a full bleed... now I'm no pro at this stuff. So will be keeping an eye on it.

Good luck with yours let us know how you get on incase theres something else I should be checking.

[bren]

Have a look here, I know most of it is not relevent but there is a part in it about adjusting the piston. Hope it helps

http://roadsterireland.com/index.php?topic=29.0

[mx5ash]

Can't veiw that link without being a member Bren.

[bren]

sorry , didnt realise that. I think there is something on the miata forum, i'll see if i can find it and post a link

[bren]

http://www.miata.net/garage/brakepad.html

Try this link to see how to adjust pistons

[sabik]

Ah Mark, how'd you get on with this problem? Mine worked fine for 2months but noticed it had creeped back in over the last while.. Not a happy bunny! Did you have anyjoy?